Coupon Code not found

[thefibreshop]

I have a customer who just tried placing an order via Safari on her iPad and was paying via PayPal. She was going to use a coupon code I sent to her as well. She got through all of the steps, including a successful PayPal authorization but nothing happened when she clicked the Place Order button. And now her coupon code is gone from her account even though the transaction didn't go through. I had her remove everything from her cart as well hoping that would reset the system. 

Has this happened to anyone else's customers?

[JustinC]

Just to be clear, after processing the payment again, the coupon code isn't working for the customer? Are you unable to find the code again from Square Online > Items > Coupons?